One-piece blind nut assembly

Abstract

A one-piece blind nut, usable for flush attachment to a workpiece by axially collapsing the nut through the use of a mandrel and an anvil, includes a body member with an internally threaded end portion which receives the threaded end portion of the mandrel. An aperture of predetermined diameter is provided in the workpiece, and the blind nut, assembled to the mandrel, is inserted through the aperture. The end of the nut opposite the threaded portion includes a serrated exterior portion which is used to secure the blind nut to the workpiece in a non-rotating relationship without the use of a countersink in the workpiece.

We claim: 
     
       1. A one-piece blind nut for flush attachment to a workpiece wherein the blind nut is attached to the workpiece by axially collapsing the nut by use of a mandrel received within the nut and by an anvil which bears against one end of the nut, said nut comprising: a body member having an internally threaded portion at one end thereof for receipt of the mandrel,   a serrated exterior end portion to secure the nut in nonrotating relation to the workpiece,   said body member including a circumferentially continuous deformable wall portion extending between the serrated end portion and the threaded portion,   means forming a cavity including a base in said body member bounded by said deformable wall portion and said cavity having an internal diameter greater than the diameter of said threaded portion,   said deformable wall being spaced radially outwardly of said threaded portion by said base and forming an enlarged open end of said blind nut,   said base extending radially inwardly between said deformable wall and said threaded portion and having a radial dimension between the deformable wall and the threaded portion greater than the cross-sectional dimension of the thickest portion of the wall portion between the serrated end portion and the threaded portion,   the external diameter of said body member in the portion thereof forming the deformable wall being so coordinated and correlated to be received within a workpiece having an aperture therein of a predetermined diameter and said external diameter being greater than the external diameter of the major portion of the threaded end,   the diameter of said cavity and the length thereof being so coordinated and correlated with the diameter and length of the mandrel to be threadably received in the threaded portion as to provide a clearance between the outer surface of said mandrel and the inner wall of said cavity while providing an annular clearance chamber to the rear and radially outwardly of the threaded portion of said nut, and   said deformable wall being contiguous with said serrated end portion and having a cross-section at least equal to or less than the cross-section of the remaining portion of the wall between the serrated exterior and the threaded portion and said wall being operative to deform as the mandrel and anvil are moved axially to each other to form a radially outwardly extending fold and being operative as said serrated end enters the workpiece to flow into said clearance to form an inwardly projecting fold.   
     
     
       2. A one-piece blind nut as set forth in claim 1 wherein said serrated exterior end portion is spaced from said one end of said nut. 
     
     
       3. A one-piece blind nut as set forth in claim 1 wherein said serrated end portion includes axially extending crests and valleys, the diameter of said crests being greater than the diameter of said body member and greater than the aperture into which the blind nut is to be assembled. 
     
     
       4. A one-piece blind nut as set forth in claim 1 wherein said deformable wall is tapered in cross-section and the thinnest portion thereof is adjacent to said serrated end. 
     
     
       5. A blind nut for flush attachment to a workpiece wherein the blind nut is attached to the workpiece by use of a mandrel received within the nut and by an anvil which bears against one end of the nut, said nut comprising; a body member having an internally threaded portion at one end thereof for receipt of the mandrel,   means on an end portion and engageable in the material of the workpiece to secure the nut in nonrotating flush relation to the workpiece,   said body member including a circumferentially continuous wall portion extending between the securing means and the threaded portion,   means forming a cavity including a base in said body member,   the external diameter of said body member in the portion thereof forming the wall being so coordinated and correlated to be received within a workpiece having an aperture therein of a predetermined diameter and said external diameter being greater than the external diameter of the major portion of the threaded end,   the dimensions of said cavity being proportioned with respect to the dimensions of the mandrel to be received in the threaded portion as to provide an annular chamber at the base of said cavity,   said deformable wall being spaced radially outwardly of said threaded portion by said base and forming an enlarged open end of said blind nut,   said base extending radially inwardly between said deformable wall and said threaded portion and having a radial dimension between the deformable wall and the threaded portion greater than the cross-sectional dimension of the thickest portion of the wall portion between the means engageable with the workpiece and the threaded portion,   said deformable wall between said securing means and said base being tapered and including a portion immediately adjacent the securing means which is thinner than the remaining portion of said wall and a portion adjacent to said base which is the thickest portion of said wall, and   said wall being deformable against the face of said workpiece to form a locking ring as the mandrel and anvil are moved relative to each other and to flow axially to form a radially inwardly extending portion which flows into said chamber during installation of said nut.   
     
     
       6. A blind nut as set forth in claim 5 wherein the outer surface of said wall is tapered.   
     
     
       7. A blind nut as set forth in claim 5 wherein the cavity is of a diameter greater than the mandrel and is bounded by said deformable wall portion, the cross-section of said wall being proportioned to provide a clearance between the outer surface of the wall and the aperture, and said axial flow of the wall being in the clearance formed between the mandrel and the aperture in the workpiece.   
     
     
       8. A blind nut as set forth in claim 5 wherein said securing means is serrations made up of crests and valleys, the diameter of the crest portion being greater than the diameter of the aperture into which said nut is to be received.   
     
     
       9. A blind nut as set forth in claim 8 wherein said serrations are spaced axially inwardly from the end of the nut. 
     
     
       10. A blind nut as set forth in claim 5 wherein the diameter of the body at the portion thereof which is threaded is less than the diameter of the remainder of said body. 
     
     
       11. A blind nut as set forth in claim 5 wherein the nut is of one piece. 
     
     
       12. A blind nut as set forth in claim 5 wherein the nut is a one-piece metal nut. 
     
     
       13. A one-piece metallic blind nut for flush attachment to a workpiece wherein the blind nut is attached to the workpiece by collapsing the nut by use of a mandrel received within the nut and by an anvil which bears against one end of the nut, said nut comprising: a body member having an internally threaded portion at one end thereof for receipt of the mandrel,   serration means at one end of said nut to secure the nut in nonrotating relation to the workpiece,   said body member including an imperforate continuous deformable wall portion extending between said serration means and the threaded portion,   means forming a cavity including a base in said body member bounded by said deformable wall portion,   the external diameter of said body member in the portion thereof forming the deformable wall being so coordinated and correlated to be received within a workpiece having an aperture therein of a predetermined diameter and said external diameter being greater than the diameter at the free end of the internally threaded portion thereof,   said deformable wall being spaced radially outwardly of said threaded portion by said base and forming an enlarged open end of said nut,   said base extending radially inwardly between said deformable wall and said threaded portion and having a radial dimension between the deformable wall and the threaded portion greater than the cross-sectional dimension of the thickest portion of the wall portion between the serration means and the threaded portion,   the diameter of said cavity and the length thereof being so coordinated and correlated with the diameter and length of the mandrel to be threadably received in the threaded portion as to provide a clearance between the outer surface of said mandrel and the inner wall of said cavity while providing an annular clearance chamber to the rear and radially outwardly of the threaded portion of said nut, and   said deformable wall immediately adjacent to said serration means having a cross-section at least equal to or less than the cross-section of the remaining portion of the wall between the serration means and the threaded portion and the said wall being operative to deform as the mandrel and the anvil are moved axially to each other to form a radially outwardly extending fold and operative as said serration means enters the workpiece to flow into said clearance to form an inwardly projecting fold.   
     
     
       14. A one-piece blind nut as set forth in claim 13 wherein said cross-section is uniform and said wall including an external groove so located axially on said nut that one wall therof is adjacent to the inside face of the workpiece. 
     
     
       15. A one-piece blind nut as set forth in claim 13 wherein said wall is tapered with the thinnest portion of said taper being immediately adjacent to said serration means. 
     
     
       16. A one-piece blind nut as set forth in claim 15 wherein the outer surface of said wall is tapered relative to the inner surface thereof. 
     
     
       17. A one-piece metallic blind nut for flush attachment to a workpiece wherein the blind nut is attached to the workpiece by axially collapsing the nut comprising: a body member having an internally threaded portion at one end thereof   the threaded end thereof including an outer tapered wall portion,   serration means at one end of said nut to secure the nut in nonrotating relation to the workpiece,   said body member including an imperforate deformable wall portion extending between said serration means and the threaded portion,   means forming a cavity including a base in said body member bounded by said deformable wall portion and said cavity having an internal diameter greater than the diameter of said threaded portion,   the external diameter of said body member in the portion thereof forming the deformable wall being proportioned to be received within a workpiece having an aperture therein of predetermined diameter,   the deformable wall being spaced radially outwardly of said threaded portion by said base and forming an enlarged open end of said blind nut,   said base extending radially inwardly between said deformable wall and said threaded portion and having a radial dimension between the deformable wall and the threaded portion greater than the cross-sectional dimension of the thickest portion of the wall portion between the serration means and the threaded portion, and   said deformable wall between said serration means and said base being tapered and including a portion immediately adjacent said serration means which is thinner than the remaining portion of said wall and including a portion adjacent to saod base which is the thickest portion of said wall.